That requires a truly astounding amount of material. Unless the cost to place it in orbit gets within an order of magnitude of our current terrestrial freight, it's not happening.
Best bet is to construct these things in orbit, with materials sourced in orbit. But now you have a chicken and egg problem - need to send an incredible amount of material (and people) in order to (potentially!) save in the future.
Best bet is to construct these things in orbit, with materials sourced in orbit. But now you have a chicken and egg problem - need to send an incredible amount of material (and people) in order to (potentially!) save in the future.